A kind of granular renovation agent and preparation method thereof for administering cadmium-arsenic combined pollution farmlandTechnical field
The present invention relates to agricultural environment child care and recovery technique field, and in particular to a kind of improvement cadmium-arsenic combined pollution agricultureThe granular renovation agent in field and preparation method thereof.
Background technology
China's soil environment overall state causes anxiety, and some areas pollution is more serious, it has also become builds up well-off society comprehensivelyOne of protrusion short slab.In May, 2016《Soil Pollution Control action plan》It proposes：By 2020, national soil pollution addedWeight trend is tentatively contained that soil environment quality totally keeps stablizing, and farming land and construction land safety of soil environment obtainBasic guarantee, soil environment risk obtain basic management and control.By 2030, become better during national soil environment quality is steady, farming land andConstruction land safety of soil environment obtains effective guarantee, and soil environment risk obtains comprehensive management and control.To the middle of this century, soil ringBorder quality improves comprehensively, and the ecosystem realizes benign cycle.
Soil pollution exists simultaneously other pollutants usually based on a certain pollutant, i.e. combined pollution problem.It is reported that cultivated area nearly 2,500 ten thousand hm of the current China by heavy metal pollutions such as Cd, As, Cr, Pb2, account for about total area under cultivation1/5.There are about the farmlands of half for South China by toxic heavy metal contaminations such as Cd, As, Yangtze River Delta Area major part farmland byTwo or more heavy metal pollutions, therefore, oneself becomes an important environmental problem to soil heavy metal combined pollution, to healthIt causes to seriously threaten with national food security.
Currently, the technology or product in cadmium-arsenic combined pollution farmland can be repaired simultaneously by having occurred some.Chinese patent ShenPlease (application number 201610079927.8) discloses a kind of heavy metal cadmium, lead, arsenic combined contamination soil renovation agent and its preparation sideMethod, renovation agent consist of the following compositions by weight percentage：Biomass carbon 30-50%, diatomite 5-10%, sodium bentonite5-10%, activated alumina 5-10%, dithiocar-bamate 10-20%, ethylenediamine tetra-acetic acid 5-10%, tartaric acid 5-10%, polyacrylamide 5-10%, dodecyl sodium sulfate 5-10%；Preparation method is：Biomass carbon, diatomite, sodium base are swollenMoisten soil, activated alumina, ethylenediamine tetra-acetic acid, tartaric acid, polyacrylamide, dodecyl sodium sulfate to stir by above-mentioned mass ratioMixing, then the dithiocar-bamate of corrresponding quality ratio is added, it stirs, the soil remediation preparedAgent.It is compound that Chinese patent application (application number 201710243623.5) discloses a kind of charcoal base for arsenic cadmium pollution soil reparationMaterial and its application are prepared into charcoal, then with certain solid-to-liquid ratio and iron salt solutions using agricultural crop straw as raw material by charingMixing, solution ph is adjusted during this both to be made to be co-precipitated, and pyrolysis forms based composite material of carbon, square in conjunction with turning over, sprinkle water etc.Method can be substantially reduced available state arsenic, cadmium content.
But these products the problem of still having the following aspects：One, only specify renovation agent to heavy metal-polluted soilThe reduction of leachability and validity acts on, unknown to the coupling repair of Soil-crops；Two, medicament active ingredient is concentratedIt works in the same time, does not adapt to absorbing rule of the crops to arsenic, cadmium, remediation efficiency is relatively low；Three, raw material components are excessivelyComplexity, manufacturing cost are higher, it is difficult to promote the use of a large area.
Invention content
For the deficiencies in the prior art, the purpose of the present invention is to provide a kind of adaptation crops to absorb heavy metalRule can repair cadmium, arsenic combined contamination soil, while effectively reduce the granular reparation medicament of cadmium and arsenic content in agricultural product.
The present invention realizes above-mentioned purpose by following technical proposals：
A kind of granular renovation agent for administering cadmium-arsenic combined pollution farmland, is made of the raw material of following parts by weight：Sodium selenite(Na2SeO3) 0.05-0.1 parts by weight, sulphur 20-40 parts by weight, calcium magnesium phosphate 20-40 parts by weight, calcium chloride 5-15 parts by weight,Bodied ferric sulfate 30-50 parts by weight and bentonite 10-30 parts by weight.
Preferably, a kind of granular renovation agent for administering cadmium-arsenic combined pollution farmland, is made of the raw material of following parts by weight：0.05 parts by weight of sodium selenite, 20 parts by weight of sulphur, 20 parts by weight of calcium magnesium phosphate, 5 parts by weight of calcium chloride, bodied ferric sulfate 3010 parts by weight of parts by weight and bentonite.
The renovation agent is graininess, repairs particle by crop and soil remediation particle two kinds of particles form, wherein cropThe structure for repairing particle is two layers, and internal layer is nutritive layer, is made of sodium selenite and calcium magnesium phosphate, and outer layer is to be formed by sulphurCoatings；Soil remediation particle is made of calcium chloride, bodied ferric sulfate and bentonite.
It is 2-4mm that the crop, which repairs particle and the grain size of soil remediation particle,.
The sodium selenite is pulvis, 95% or more purity；Soluble silicon is (with SiO in the calcium magnesium phosphate2Meter) containAmount is not less than 20%, and the content of alkali point (in terms of CaO) is not less than 45%, and pulvis (crosses 200 mesh sieve)；The bodied ferric sulfate is pureDegree is not less than 95%, and all iron content is not less than 20%, pulvis；The bentonite is sodium bentonite, and pulvis (crosses 200 mesh sieve)；Sulphur is industrial sulphur, 98% or more purity.
A kind of preparation method of granular renovation agent that administering cadmium-arsenic combined pollution farmland comprising following steps：
A, crop repairs particulate material mixing：Sodium selenite is added in calcium magnesium phosphate, is uniformly mixed；
B, crop repairs grain granulation：The materials of step A after mixing are gone to through charging spout in disk, are made with diskGrain method prepares particle, then dries；
C, crop repairs granule coating：Use sulphur as coated fertilizer, by heated fluidized bed jet flow coating method by sulphurParticle surface of the uniform coating after step B drying, obtains crop and repairs particle；
D, soil remediation particulate material mixes：Bodied ferric sulfate, calcium chloride and bentonite are uniformly mixed；
E, soil remediation grain granulation：The materials of step D after mixing are gone to through charging spout in disk, are made with diskGrain method prepares particle, and then drying obtains soil remediation particle；
F, two kinds of particles blend：The crop that step C and step E are obtained repairs particle and soil remediation particle mixesIt is even, it is governed the granular renovation agent in cadmium-arsenic combined pollution farmland.
Further, the condition dried described in step B and step E is to be dried 15 minutes at 300 DEG C.
Further, the grain diameter that prepared by the step B is 1-2mm；Sulphur film thickness is 1-2mm in the step C,It is 2-4mm that the crop, which repairs grain diameter,；Soil remediation grain diameter prepared by the step E is 2-4mm.
Above-mentioned granular renovation agent is administering cadmium-farmland application of arsenic combined pollution, includes the following steps：
(1) renovation agent is spread fertilizer over the fields：5-10 days before crop seeding or transplanting, the granular renovation agent is uniformly spread fertilizer over the fieldsAgricultural land soil surface；
(2) it stirs：Renovation agent and soil are stirred evenly；
(3) add water cure：For nonirrigated farmland, watering is cured to being saturated；For paddy field, pour water to waterflooding state, waterflooding thicknessFor 2-8cm, curing.
Further, the application is as follows：
A, sample detecting：Quasi- reparation agricultural land soil sample, analysis pH, full cadmium (Cd), available Cd are acquired with five-spot(Cd), the physicochemical properties such as full arsenic (As), available state arsenic (As)；
B, dosage is calculated：According to the physicochemical property measured, being ploughed using Nei Meiluo composite index law unit of account areas is neededThe renovation agent dosage of application, specific algorithm are as follows：
| PIt is comprehensive(comprehensive pollution indexes) | 1<PIt is comprehensive≤2 | 2<PIt is comprehensive≤3 | 3<PIt is comprehensive |
| Renovation agent dosage (kg/ mus) | 80-110 | 120-150 | 160-190 |
Note：
In formula：PiFor the pollution index of i heavy metal elements；CiFor i content of beary metal measured values；SIFor soil environment qualityStandard value (national grade ii standard value), PIt is comprehensiveIt is the comprehensive pollution indexes of sampled point；PimaxFor sampled point heavy metal contaminants individual eventMaximum value in pollution index；For index of single factor average value；
C, it applies：5-10 days before crop seeding or transplanting, according to the calculated reparation agent doses of step B by the grainShape renovation agent uniformly spreads fertilizer over the fields agricultural land soil surface；
D, it stirs：Renovation agent and soil are stirred evenly using rotary cultivator；
E, add water cure：For nonirrigated farmland, watering is cured to being saturated；For paddy field, pour water to waterflooding state, waterflooding thickness2-8cm, curing.
Compared with prior art, the advantages of the present invention are：
1, using coagulating sedimentation, suction-operated, antagonism of ions, nutrient balance, in vivo the complex repairations principle such as fixed, multidimensionalDegree realizes the safe utilization in contaminated cadmium-arsenic combined pollution farmland, arable land.Renovation agent prepared by the present invention is being manured into soil and is addingAfter water cure, the ferric sulfate contained by soil remediation particle therein can discharge quickly, and a large amount of [Fe is formed in the soil liquid(H2O)6]3+、Fe2(OH)3]3+、[Fe3(OH)2]4+Equal complex ions, facile hydrolysis form polynuclear complex, these complex compounds can be strongColloidal particles in the strong absorption soil liquid promote colloidal particles mutually to collide, are formed by the effects that absorption, bridge formation, crosslinkingCotton-shaped coagulating sedimentation；AsO simultaneously33-、 AsO45-It can be with Fe (OH)3It reacts and generates FeAsO3And FeAsO4, generationFeAsO3、FeAsO4Precipitation is repaired agent hydrolysate volume and sweeps, and deposits together.While ferric sulfate discharges, due to havingHuge specific surface area, arsenic acid radical ion that bentonite can be remaining in the strong adsorption soil liquid, arsenite ion, cadmium fromSon, for crops, calcium ion can form competition absorption relationship with cadmium ion, and the calcium ion in soil remediation particle can be intoEnter into the soil liquid, to inhibit absorption of the crops to cadmium.
For rice, tillering regularity to pustulation period is Rice Absorbed Cadmium, the arsenic stage the most vigorous, with cropsGrowth, the coating that crop repairs particle surface layer can decompose gradually, soluble silicon and sodium selenite therein also can slow release,Reach maximum rate in tillering regularity, and silicon and trivalent arsenic share the absorbing path of crop root, silicon is formed with trivalent arsenic and is competedAbsorption relationship；Silicon can also increase rice cell wall thickness, reduce cell leakage, hinder cadmium in rice plant to seedTransfer；Selenium has certain inhibition for the transfer upward in rice plant of cadmium, arsenic；Crop repair particle coating beSulphur, and sulphur is the required moderate-element of crops, can also be promoted the formation of sulfydryl after rice absorbing, thus will be moreCadmium is fixed in rice cell wall, achievees the purpose that repair cadmium-arsenic combined pollution farmland.Similarly, for other farmingsFor object, the renovation agent using the present invention equally achievees the purpose that repair cadmium-arsenic combined pollution farmland.Therefore, it usesThe renovation agent of the present invention can in all directions repair cadmium-arsenic combined pollution farmland.
2, crop is repaired particle and is designed using slow-releasing granules, more adapts to the growth rhythm of crops, entire repair processOnly need applied once.With the filling draining in farmland and the eluviation of soil itself, in traditional medicament silicon and selemium nutrition byGradually it is lost in.And the present invention can calcium magnesium phosphate and sodium selenite be prepared into particle, and in surface coatings, active ingredient is made slowly to releaseIt puts, effectively prevents the loss of silicon and selenium, improve remediation efficiency.
3, using conveniently, secondary pollution will not be caused：Renovation agent prepared by the present invention is graininess, easy to use, applicationWhen there is no dust generation, avoid the health hazard to operating personnel and the pollution to air；In addition, the present invention use it is mainRaw material will not cause secondary pollution to soil.
4, renovation agent produced by the present invention is graininess, is made of two kinds of particles, and respectively crop repairs particle and soilParticle is repaired, grain size is 2-4mm, wherein the structure that crop repairs particle is two layers, and internal layer is nutritive layer, by sodium seleniteIt is formed with calcium magnesium phosphate, outer layer is coatings, is made of sulphur.Soil remediation particle is by calcium chloride, bodied ferric sulfate and swellingLocal soil type at.Soluble silicon is (with SiO in renovation agent prepared by the present invention2Meter) content is 3.81%-4.63%, the content of Se is218-255mg/kg, alkali point (in terms of CaO) content are 12.4%-17.9%, and Fe contents are 8.11%-9.32%, water content2.3%-3.58%, sustained release nutrient are selenium and soluble silicon, 28 days accumulative nutrient release rates of sustained release nutrient are 33.1%~37.3%, sustained release fertilizer releasing period is 55-65 days.
Description of the drawings
Fig. 1 is that the crop of the present invention repairs the structural schematic diagram of particle, wherein entitled corresponding to reference numeral：1-Nutritive layer, 2- coatings.
Fig. 2 is that 2 treated paddy soils of processing and untreated rice soil in processing 1 are effective in embodiment 4State content of beary metal comparison diagram；
Fig. 3 is that 2 rice and cadmium, the abio-arsenic residues comparison diagram in rice in processing 1 are handled in embodiment 4；
Fig. 4 is that 2 treated celery soil of processing and untreated celery soil in processing 1 are effective in embodiment 5State content of beary metal comparison diagram；
Fig. 5 is that the celery overground part of processing 2 is compared with cadmium, total arsenic content in the celery overground part of processing 1 in embodiment 5Figure.
Specific implementation mode
Sodium selenite used in the following example is pulvis, 95% or more purity；Calcium magnesium phosphate is by Zhongxiang District Hubei ProvinceFertile plump industry Co., Ltd provides, and soluble silicon is (with SiO2Meter) content is not less than 20%, and the content of alkali point (in terms of CaO) is notLess than 45%, pulvis (crosses 200 mesh sieve)；Bodied ferric sulfate is provided by six good fortune Environmental Protection Technology Co., Ltd of Changsha, and purity is not less than95%, all iron content is not less than 20%, pulvis；Bentonite is sodium bentonite pulvis (crossing 200 mesh sieve), by city of Ningxiang of Hunan ProvinceCertain mineral powder factory provides；Sulphur is industrial sulphur, is provided by Wuhan Xin Yongqing Chemical Co., Ltd.s, 98% or more purity.
Alleged " part " refers both to " parts by weight " in following example 1-3.
Embodiment 1：A kind of granular renovation agent for administering cadmium-arsenic combined pollution farmland, preparation method are as follows：
0.05 part of sodium selenite is added in 20 parts of calcium magnesium phosphate, is uniformly mixed, the material after mixing is gone to through charging spoutIn disk, the particle that grain size is 1mm is prepared with disc granulation method, is then dried 15 minutes under the conditions of 300 DEG C；Utilize 20 parts of sulphurSulphur is as coating material, the particle surface by heated fluidized bed jet flow coating method by the uniform coating of sulphur after above-mentioned drying,Sulphur film thickness 1mm repairs particle to prepare the crop that grain size is 2mm.By 30 parts of bodied ferric sulfates, 5 parts of calcium chloride and10 parts of bentonites are uniformly mixed, and are gone in disk through charging spout, are prepared the particle that grain size is 2mm with disc granulation method, thenIt is dried 15 minutes under the conditions of 300 DEG C and obtains soil remediation particle.Crop derived above is finally repaired into particle and soil remediationParticle is uniformly mixed, and is governed the granular renovation agent in cadmium-arsenic combined pollution farmland.
The structural schematic diagram that the crop of preparation repairs particle is as shown in Figure 1, wherein 1 is by sodium selenite and calcium magnesium phosphateThe nutritive layer of composition, 2 be the coatings formed by sulphur.
Embodiment 2：A kind of granular renovation agent for administering cadmium-arsenic combined pollution farmland, preparation method are as follows：
0.08 part of sodium selenite is added in 30 parts of calcium magnesium phosphate, is uniformly mixed, the material after mixing is gone to through charging spoutIn disk, the particle that grain size is 1.5mm is prepared with disc granulation method, is then dried 15 minutes under the conditions of 300 DEG C；Utilize 40 partsSulphur is as coating material, the particle table by heated fluidized bed jet flow coating method by the uniform coating of sulphur after above-mentioned dryingFace, sulphur film thickness 2mm repair particle to prepare the crop that grain size is 3.5 mm.By 50 parts of bodied ferric sulfates, 10 parts of chlorineChange calcium and 30 parts of bentonites are uniformly mixed, is gone in disk through charging spout, that grain size is 3.5mm is prepared with disc granulation methodGrain, then dries 15 minutes under the conditions of 300 DEG C and obtains soil remediation particle.Crop derived above is finally repaired into particle and soilEarth is repaired particle and is uniformly mixed, and the granular renovation agent in cadmium-arsenic combined pollution farmland is governed.
Embodiment 3：A kind of granular renovation agent for administering cadmium-arsenic combined pollution farmland, preparation method are as follows：
0.1 part of sodium selenite is added in 40 parts of calcium magnesium phosphate, is uniformly mixed, the material after mixing goes to circle through charging spoutIn disk, the particle that grain size is 2mm is prepared with disc granulation method, is then dried 15 minutes under the conditions of 300 DEG C；Utilize 30 parts of sulphurSulphur is as coating material, the particle surface by heated fluidized bed jet flow coating method by the uniform coating of sulphur after the drying, sulphurFilm thickness 2mm repairs particle to prepare the crop that grain size is 4mm.By 40 parts of bodied ferric sulfates, 15 parts of calcium chloride and 20 partsBentonite is uniformly mixed, and is gone in disk through charging spout, the particle that grain size is 4mm is prepared with disc granulation method, then 300It is dried 15 minutes under the conditions of DEG C and obtains soil remediation particle.Crop derived above is finally repaired into particle and soil remediation particle mixesIt closes uniformly, is governed the granular renovation agent in cadmium-arsenic combined pollution farmland.
The comprehensive technical indexes of the obtained granular renovation agents of embodiment 1-3 are detected, the results are shown in Table 1.
The comprehensive technical indexes of renovation agent made from 1 embodiment 1-3 of table
Note：1. " % " refers to mass percentage in table 1 (except release rate)；It is sustained 28 days accumulative release rates of nutrient, delaysIt is basis to release fertilizer releasing period《Slow release fertilizer》(GB/T23348-2009) and《The measurement of water-soluble fertilizer sodium, selenium, silicone content》The detection that (NY/T 1972-2010) is carried out.
2. it includes selenium and soluble silicon to be sustained nutrient, nutritive layer is uniformly mixed by calcium magnesium phosphate and selenium, the speed of releaseRate is suitable, so indicating that renovation agent sustained release is supported in table to be sustained 28 days accumulative release rates, the sustained release fertilizer releasing period of nutrient seleniumThe release conditions divided.
Embodiment 4：Cadmium-arsenic combined pollution rice terrace repairing test
In April, 2017-, September was in the Cd-As combined pollutions rice field near year Hunan Province's Chenzhou City persimmon bamboo plantation Pb-Zn ore districtCarry out rice field cell repairing test.Rice varieties are strain two excellent 505, are purchased in Hunan Ya Hua seeds Co., Ltd.CellSize is 4m × 5m (20m2), separated with the ridge of high 30cm, width 30cm, agricultural film is applied on ridge, the single single filling of cell prevents mutuallyMutually string water, string fertilizer.Two processing of setting：
Handle 1 (control)：It is planted according to local traditional approach, does not apply any renovation agent；
Processing 2：It is accustomed to using the obtained granular renovation agent for administering cadmium-arsenic combined pollution farmland of embodiment 1+according to localityMethod is planted.
3 repetitions are arranged in each processing, totally 6 cells.
Experimental field soil is detected for acquisition, according to the data of detection, calculates comprehensive pollution indexes, so that it is determined that processing 2The amount of application of renovation agent, it is specific as follows：
A, sample detecting：Quasi- reparation arable soil sample is acquired with five-spot, analyzes its pH, full cadmium (Cd), effective cadmium(Cd), the physicochemical properties such as full arsenic (As), effective arsenic (As).
Detect the basic physical and chemical of obtained experimental field soil：pH：5.78 Quan Ge：1.92mg/kg available Cd：0.85mg/kg, full arsenic：75.7mg/kg, available state arsenic：2.95mg/kg.
B, dosage is calculated：According to the physicochemical property measured, being ploughed using Nei Meiluo composite index law unit of account areas is neededThe renovation agent dosage of application, specific algorithm such as the following table 2：
Table 2
| PIt is comprehensive(comprehensive pollution indexes) | 1<PIt is comprehensive≤2 | 2<PIt is comprehensive≤3 | 3<PIt is comprehensive |
| Renovation agent dosage (kg/ mus) | 80-110 | 120-150 | 160-190 |
Note：In formula：PiFor the pollution index of i heavy metal elements；CiFor content of beary metal measured value；SIFor《Soil environment matterAmount standard》(GB 15618-1995) secondary standard value), PIt is comprehensiveIt is the comprehensive pollution indexes of sampled point； PimaxFor a sampled point huge sum of moneyBelong to the maximum value in pollutant monomial pollution exponent；For index of single factor average value.
According to sample detecting data, P is calculatedIt is comprehensiveIt is 5.52, grain prepared by the embodiment of the present invention 1 that processing 2 usesShape renovation agent amount of application is set to 180kg/ mus.5 days before rice transplanting, improvement cadmium-arsenic combined pollution agriculture prepared by embodiment 1The granular renovation agent in field according to 180kg/ it is per mu it is even spread fertilizer over the fields processing 2 agricultural land soil surface, using rotary cultivator by renovation agent withSoil stirs evenly, and pours water to waterflooding state, waterflooding thickness 5cm, curing, then carries out rice transplanting, Fertilization Level and otherField management measure and processing 1 are completely the same.When rice maturation, acquisition soil, rice sample are detected analysis.
1. the influence of available Cd, available state arsenic content in pair paddy soil
Treated paddy soil and untreated rice soil available content of beary metal in processing 1 in processing 2Comparison diagram, as shown in Fig. 2, figure it is seen that the soil available cadmium of 1 (control) of processing, available state arsenic content are respectively0.88mg/kg, 2.86mg/kg handle 2 soil available cadmium, available state arsenic content is respectively 0.79mg/kg, 1.02mg/Kg, relatively handle 1 (control) reduces by 10.23%, 64.34% respectively, and there are significant differences.The reparation of this explanation application present inventionAgent can effectively reduce the validity of cadmium and arsenic in soil simultaneously.
2. the influence of cadmium, arsenic content in pair rice
Processing 2 and content of beary metal comparison diagram in the rice of processing 1, as shown in figure 3, from figure 3, it can be seen that processing 1Cadmium content is 0.96mg/kg in the rice of (control), is more than《National food safety standard pollutants in food is limited the quantity》(GB3.8 times of limits value in 2762-2017)；Cadmium content is 0.18mg/kg in the rice of processing 2, and the relatively rice of processing 1 reduces81.25%, and the requirement that is up to state standards.It is 0.77mg/kg to handle abio-arsenic residues in the rice of 1 (control), is more than《FoodThe safe national standard pollutants in food limitation of product》2.85 times of limits value in (GB 2762-2017)；Nothing in the rice of processing 2Machine arsenic content is 0.17mg/kg, and the relatively rice of processing 1 reduces by 77.92%, and the requirement that is up to state standards.This explanation application is originallyThe renovation agent of invention can effectively reduce the content of cadmium and arsenic in rice simultaneously.
Embodiment 5：Cadmium-arsenic combined pollution vegetable field repairing test
October in May, 2017-the Cd-As combined pollution vegetable fields near year Hunan Province's Chenzhou City persimmon bamboo plantation Pb-Zn ore districtInterior development cell repairing test.The vegetables of plantation are celery, and kind is golden yellow bones of the dead.The m of cell size 2m × 8 (16m2), makeFurrow, if the row's of filling ditch, it is single it is single fill, prevent from go here and there mutually water, go here and there it is fertile.Two processing of setting：
Handle 1 (control)：It is planted according to local traditional approach, does not apply any renovation agent；
Processing 2：It is accustomed to using the obtained granular renovation agent for administering cadmium-arsenic combined pollution farmland of embodiment 2+according to localityMethod is planted.
3 repetitions are arranged in each processing, totally 6 cells.
Experimental field soil is sampled and detected according to the method for embodiment 4, according to sampled data, detection is experimental field nativeThe basic physical and chemical of earth is：pH：5.89 Quan Ge：1.27mg/kg available Cd：0.42mg/kg, full arsenic：58.4mg/kg,Available state arsenic：P is calculated in 1.85mg/kgIt is comprehensiveIt is 3.6, amount of application is determined according to the following table 3.
Table 3
| PIt is comprehensive(comprehensive pollution indexes) | 1<PIt is comprehensive≤2 | 2<PIt is comprehensive≤3 | 3<PIt is comprehensive |
| Renovation agent dosage (kg/ mus) | 80-110 | 120-150 | 160-190 |
So the renovation agent dosage that processing 2 uses is set to 160kg/ mus.It is sowed first 10 days in celery, embodiment 2 is madeThe granular renovation agent in standby improvement cadmium-arsenic combined pollution farmland handles 2 agricultural land soil surfaces according to 160kg/ even spread fertilizer over the fields per mu,And so that it is stirred evenly with soil using rotary cultivator, add water to soil moisture content saturation, curing, then sow, Fertilization Level withOther field management measures and processing 1 are completely the same, when celery maturation, acquisition soil, celery overground part sample, and detection pointIt analyses, the celery overground part in the present invention refers to the mixture of stem of celery and leaf.
1. the influence of pair celery soil available Cd, available state arsenic content
Treated celery soil is compared with untreated soil available content of beary metal in processing 1 in processing 2Figure, as shown in figure 4, from fig. 4, it can be seen that the soil available cadmium of 1 (control) of processing, available state arsenic content are respectively0.46mg/kg, 1.84mg/kg handle 2 soil available cadmium, available state arsenic content is respectively 0.38mg/kg, 0.35mg/Kg, relatively handle 1 (control) reduces by 17.39%, 80.98% respectively, and there are significant differences.The reparation of this explanation application present inventionAgent can effectively reduce the validity of cadmium and arsenic in celery soil simultaneously.
2. the influence pair celery overground part cadmium, arsenic content
Processing 2 and content of beary metal comparison diagram in the celery overground part of processing 1, as shown in figure 5, can from Fig. 5Go out, it is 0.69mg/kg to handle cadmium content in the celery overground part of 1 (control), is more than《It is polluted in national food safety standard foodObject is limited the quantity》2.45 times of limits value in (GB 2762-2017)；Cadmium content is 0.16mg/kg in the celery overground part of processing 2, more rightAccording to reduction by 76.81%.It is 1.55mg/kg to handle total arsenic content in the celery overground part of 1 (control), is more than《Food security countryPollutant is limited the quantity in standard food》2.1 times of limits value in (GB 2762-2017)；Total arsenic content in the celery overground part of processing 2For 0.32mg/kg, relatively control reduces by 79.35%, and the requirement that is up to state standards.The renovation agent of this explanation application present invention can be withCadmium and arsenic content in celery overground part are effectively reduced simultaneously.
In summary, the granular renovation agent in improvement cadmium-arsenic combined pollution farmland of the invention is effectively reducing agricultural land soilOn the basis of middle cadmium and arsenic are active, the content of heavy metal cadmium and arsenic in agricultural product can be significantly reduced simultaneously, reaches national markAlignment request.